Peptide E and its products, BAM 18 and Leu-enkephalin, in bovine adrenal medulla and cultured chromaffin cells: release in response to stimulation. Academic Article uri icon

Overview

abstract

  • Peptide E is a 25 amino acid opioid peptide which, if cleaved at the sole double basic (Lys-Arg) typical processing site, would generate two opioid fragments, the amino-terminal fragment BAM 18 and the carboxy-terminal fragment Leu-enkephalin. We have analysed extracts of bovine adrenal medulla in order to quantify these three opioid peptides (peptide E, BAM 18, and Leu-enkephalin). Here we present evidence that BAM 18 and Leu-enkephalin were present in similar amounts, whereas peptide E was present at a higher concentration. This is consistent with previous observations showing a preferential accumulation of larger peptides in the bovine adrenal, and also with the Lys-Arg bond being the principal site of cleavage of peptide E. However, when bovine adrenal chromaffin cells were maintained in culture for several days, Leu-enkephalin was found to be present in much greater amounts than was BAM 18-like immunoreactivity. The molar amounts of peptide E still exceeded the estimated levels of BAM 18 and Leu-enkephalin. We provide evidence that under conditions of basal release BAM 18 and peptide E were released, whereas Leu-enkephalin was released in much smaller amounts, if at all. On stimulation with nicotine results were consistent with an increased release of all three peptides with a preferential stimulation of Leu-enkephalin release. Under all conditions, the molar amounts of peptide E released apparently exceeded that of the other peptides. The results are discussed in terms of the regulation of partial proteolysis and the fate of peptide E.

publication date

  • December 1, 1987

Research

keywords

  • Adrenal Medulla
  • Chromaffin System
  • Enkephalin, Leucine
  • Enkephalin, Methionine
  • Enkephalins
  • Peptides
  • Protein Precursors

Identity

Scopus Document Identifier

  • 0023630820

Digital Object Identifier (DOI)

  • 10.1111/j.1471-4159.1987.tb02443.x

PubMed ID

  • 3681299

Additional Document Info

volume

  • 49

issue

  • 6